The invention concerns a foot lifter orthosis with a dorsal leg shell extending over the rear foot, which can be fixed by a strap or the like to the calf of the orthosis wearer and extends with a forefoot shell section constructed in one piece with it to a point below the foot sole region. A foot orthosis which is of similar construction with regard to the leg shell and designed as an ankle joint orthosis is described in EP 0 567 783 B1.
A significant problem with this type of foot lifter orthosis is the lack of adaptation of the foot of the orthosis wearer to the footwear worn by the orthosis wearer.
The present invention is directed to overcoming one or more of the problems set forth above.
In accordance with the present invention there is provided a foot lifter orthosis having a dorsal leg shell extending over the rear foot and made of plastic, which can fixed by a strapping means to the calf of the orthosis wearer and which has a forefoot shell section constructed in one piece which extends to a point below the foot sole region, wherein the leg shell exhibits a low resistance in dorsal foot bending and a high resistance compensating for the foot and shoe mass in plantar foot bending and is made of a soft, flexible plastic and two spring wire inlays, which extend approximately parallel to and at a short distance from the inner or outer edge of the leg shell from the calf region thereof to a point below the forefoot shell section and are embedded on the rear, lower side of the leg shell.
It is an aspect of the invention to improve the foot lifter orthosis described herein with respect to its adaptation to the foot of the orthosis wearer and to the footwear worn by the orthosis wearer.
It is an aspect of the invention to improve the foot lifter orthesis described herein with respect to its adaptation to the foot of the orthesis wearer and to the footwear worn by the orthesis wearer.
The foot lifter orthosis according to the invention achieves this object by virtue of its leg shell that exhibits a low resistance in dorsal foot bending and a high resistance compensating for the foot and shoe mass in plantar foot bending. It is made of a soft, flexible plastic, e.g. a low-density polyethylene or an EVA, in which two spring steel wire inlays are embedded on the rear or lower side of the leg shell. The two spring steel wire inlays extend approximately parallel to and at a short distance from the inner or outer edge of the leg shell from the calf region thereof to a point below the forefoot shell section.
The shape of the wire inlays determines the essential properties of the orthosis. It is appropriate if the wire inlays end approximately in the lower region of the heel bone.
To improve the comfort of wearing, it is advantageous if the wire inlays are almost completely surrounded by the plastic.
To save the shoe edge of footwear worn by the orthosis wearer, it is advantageous if a central rib is provided which is formed integrally in the rear heel region of the leg shell on the rear side thereof and which protrudes beyond the shoe edge thereof when the footwear worn.
A particularly suitable plastic is a low-density polyethylene LDPE 100 which is soft enough to naturally adapt to the foot of the orthosis wearer as well as the footwear worn by the orthosis wearer, without manual finishing. According to the invention, therefore, there is provided an autoadaptive foot orthosis having wire inlays to ensure a firm orthosis construction in the plantar region. Preferably a pre-bent spring steel wire with a diameter of 1.5 to 2 mm is used, which is fixed to distance holders before deep-drawing the leg shell in order to obtain complete surrounding by the plastic. Manufacture of the leg shell by injection molding is possible.